Different systems can be used to detect outlying data in a set of time series data. The system used on a given set of time series data may need to be selected based on the characteristics of that set of time series data. Outlying data will appear differently in different types of time series data, depending on what kind of patterns would normally be expected in the time series data. Outlying data may appear differently in time series data that includes hard drive temperatures than it will in time series data that includes winter clothing sales. Detecting outlying data in a set of time series data may be useful for detecting problems in computer hardware and software. Outlying data in a time series of hard drive temperatures may show drives running too hot or indicate drive failures. Outlying data may also indicate anomalies in other types of data, such as sales data.